During a press conference this afternoon, Craig Harvey, the chief coronor investigator, said the cause of death was deferred because additional tissue studies and testing -- including toxicology, neuropathology, pulmonary and others -- must be completed. These tests should be completed in four to six weeks, he said. Once those are completed, the ongoing case can be closed.

Still, the autopsy, which took three hours to complete, revealed that Jackson's body suffered no external trauma and there was "no indication of foul play," Harvey said.

He added that Jackson, however, had been taking "some prescription medications" but could not confirm what those drugs were.

Jackson, who suffered cardiac arrest at his rented L.A. home Thursday, was pronounced dead inside the hospital's emergency room at 2:26 p.m. PST, he said. He added that because no doctor signed the death certificate, a coronor at L.A.'s coronor's office did instead.

Although some reports claim Jackson may have overdosed on Demerol, Brian Oxman -- who has served as the family's attorney for more than 20 years -- told Usmagazine.com he couldn't comment on the types of medications Jackson was taking.

"It is something which is private to Michael, and we'll have to wait for the toxicology reports before we jump to any kind of conclusions," he said. "I only know that I warned that his day may come. And lo and behold, here we are."